Introduction: This study aimed to clarify the support provided by certified nurse specialists in critical care nursing to family members who are responsible for surrogate decision-making.

Methods: Semi-structured interviews were conducted with 15 certified nurse specialists in critical care nursing, and text mining methods using KH Coder were used to extract frequently appearing words from the verbatim data obtained, and hierarchical cluster analysis and co-occurrence network analysis were conducted.

Results: The results of the analysis using words that appeared more than 25 times were classified into 10 hierarchies and 9 sub-graphs. These were further grouped to generate three categories: [bridging communication], [information sharing and collaboration] and [information gathering and decision-making facilitation].

Conclusion: Certified nurse specialists in critical care nursing provided multifaceted support to families making proxy decisions, mainly as intermediaries between physicians and families, confirming their understanding and encouraging families to make decisions based on appropriate information and perceptions.